You can cut you own if you want to give it a try.
Here's some quick dimensions of a (minor water damaged) 19" (or maybe 18" ??) atari UR pole position monitor bezel:

Folds are color coded. The bezel is in two parts of black card board glued together; the red folds are also where the the bottom piece is attatched to the large upper piece.
The inside really isn't a rectangle; the edges are curved outward to match the arcade monitor, and so the lengths aren't precise. The inside diagonal is ~18". If the front of the bezel was straight vertical, the monitor would be tilted back ~30 degrees. The blue folds are mountain folds, with the card board scored on the front side, I guess to prevent tears.
FWIW, I thought the bezel was heat warped black plastic until I removed the glass, umm, bezel (?). You know, the flat one with the instructions and other art painted on it, and protects the monitor. Are both the glass and the black cardboard "bezels"?
BTW, sorry about the pic, I use a drawing app. I wish I had a good CAD prog.
